Electric switch



June 30, 1942. J HAMMERLY 2,287,994

ELECTRIC SWITCH Filed Jan. 27, 1940 2 Sheets-Sheet l "Nil"I"I"!lllllllllllllllllm m IIIII'IIIIII'lIIII/IIIIIIIIIIIIIIIL 1o 14 INVENTOR Hngm/v J. //A MMERL Y,

June 30, 1942. H. J. HAMMERLY 87,

ELECTRIC SWITCH Filed Jan. 27, 1940 2 Sh ets-sheet 2 INVENTOR HERMAN J. HA MMERL Patented June 30, 1942 ELECTRIC SWITCH Herman J. Hammerly, Plainville, Com, assignmto The Trumbull Electric Manufacturing Company, Plainville, Conn., a corporation of Connecticut Application January 27, 1940, Serial No. 315,957

Claims.

My invention relates to electric switches and more particularly to the enclosed front operated type of switch.

An object of my invention is to provide a switch that is simple in construction and inexpensive to manufacture.

Another object is to facilitate mounting and demounting of the switch unit in the box, and connecting of wires to the terminals.

Another object is to reduce the number of fastening means necessary to connect the parts and to fasten the switch unit in the box.

Another object is to protect the stationary contact when the movable contact is moved away from it, and to effectively extinguish any arc that might form between these contacts.

In the preferred form the switch contacts are mounted in a recess at the back of an insulating base which is secured to a carrierplate by a single screw. This base and plate are secured directly to the bottom of the box by a tongue or lug on the plate which engages in a socket in the box bottom and by a single screw which passes through the base into the bottom of the box. The carrier plate has an upstanding fiange with a pivot on which the actuating lever is mounted. The base has an upstanding projection which serves to position the actuating lever and also to separate terminals. A fuse socket is mounted on the front of the base within the box. The actuating handle projects through a slot in the cover of the box. Details will be understood from the following specification.

Fig. 1 is a front view of a switch box and switch embodying one form of my invention, the cover being open.

Fig. 2 is a cross sectional view on the plane of the line 2--2 of Fig. 1, looking upwardly and with the cover closed.

Fig. 3 is a side view of the switch unit,'with a section of the bottom of the box.

Fig. 4 is an exploded perspective view of the base and associated parts.

Fig. 5 is a bottom plan view of the base showing the resilient contact arm and the insulating lever which actuates it.

Fig. 6 is a sectional view of the base taken on the plane of the line 8-8 of Fig. land Fig. 5 with a fuse socket mounted in place and the switch parts in on position.

Fig. 7 is a detail sectional view showing the switch parts in off position.

Fig. 8 is a plan view of a modified form of my invention showing a three pole assembly, some parts being eliminated for clarity.

The box body has a hinged cover ll of suitable construction. The base I3 is of insulating material such as porcelain and a layer of insulating fibre I4 is preferably interposed between the base and the carrier plate l5. A screw l8 serves to secure the base to the plate.

The plate l5 has a lug or tongue I! adapted to interlock beneath a pocket or socket l8 which is formed by striking a portion of the bottom of the box inwardly. A screw i9 extends through the base and the plate and screws into a seat in the bottom of the box, completing the support of the mechanism within the box.

The main terminals 20 and 2| are arranged at opposite corners of the base so that the wires may be brought almost straight in from the top, bottom, or sides of the box. Between them is arranged the fuse socket 22. A metal member 23 connects the terminal 2| with the outer shell of the socket 22. A center contact screw 24 extends through the base and is screwed into the contact 25 in a countersunk recess in the back and thus holds the fuse socket in place. The spring arm switch member 28 is biased toward the contact 25 and has a boss 26' for engaging the contact to close the circuit in the position of Fig. 6. This arm 28 is secured to the base in the recess 21 at the back by the terminal screw 20. The insulating lever 28 is pivoted in the recess 21 on the stud 28 which is integral with the base. The spring switch arm 28 serves to hold the lever 28 in place and the lever serves to retract the switch arm when it is interposed between the boss 28' and the adjacent wall of the base.

The lower face of the contact 25 is countersunk or set back in the recess in the base so as to leave a space 29 between the arm 28 and the contact when the circuit is opened by the interposition of the arm 28 between the boss 26' and the contact 25. This most effectively breaks the circuit. It will thus be seen that the contact 25 is housed in a recess 29 within the recess 21 between the base l3 and the fibre layer ll.

The finger lever or handle 30 is pivoted at 3| on a flange 32 which projects from the carrier plat I 5 and the lever or handle has a pin 33 which projects into a slot 34 of the lever 28 when the parts are assembled, The flange 32 has a slot 35 for the forked end of the lever 28.

The post or projection 38 integral with the base I 3 projects between the terminals 20 and 20 and serves to hold the handle 30 on its pivot 3|. Terminal 20' is provided for connection of a neutral wire or wires.

The same ideas may be embodied in a multipole switch such as the three pole switch shown in Fig. 8. Here I have shown three fuse sockets 40, 4| and 42 each with the circuit terminal as before and each having a contact at the rear such as previously shown and described. Each has a spring switch arm 43, 44 and 45, respectively, in a recess 46 in the back of the base 41. An insulating lever 48 is pivoted at 49 and has arms 50, 5! and 52 for retracting the respective switch arms in exactly the same manner as the arm 28 retracts the switch arm 26 in the first form described.

I claim:

1. An electric switch including a plate having an angular extension on one edge thereof with a slotted portion, an insulating base on said plate, a stationary contact on the base, a movablecontact biased into engagement with the stationary contact, a pivoted lever on the base for moving said movable contact out of engagement with said stationary contact, said lever having an extension movable in said slotted portion and a handle pivoted on said plate extension for actuating said lever.

2. An electric switch including a plate having an angular extension on one edge thereof, an insulating base having a plain rear surface mounted on one of the surfaces of said plate and having a hollow recess portion in said rear surface, a stationary contact on the base having one of its ends in the recessed portion thereof, a movable contact in the recessed portion biased toward engagement with said stationary contact, an insulating lever pivoted within the confines of said recessed portion to move said movable contact away fromthe stationary contact and a pivoted handle on the plate extension interlocked with said lever for actuating the same.

3. In an electric switch, an insulating base having a countersunk portion in one face, a stationary switch contact on the base recessed within the countersunk portion; a strip spring contact having a contact making portion thereof adapted to enter the countersunk portion of said insulating base and secured on the base and always biased toward engagement with the stationary contact in the countersunk portion, and

'base and having a portion adapted to close the face area of the countersunk portion, said blade being movable between a position wherein it permits movement of the spring contact so as in part to engage the stationary contact, and a position wherein it moves the spring contact out of engagement with the stationary contact and simultaneously closes the countersunk portion to provide a protective and are extinguishing air chamber for the stationary contact, the spring contact in both positions holding said blade against the base and tending to retain said blade in the two locations thereof corresponding respective to the open and closed circuit positions of the switch.

4. In an electric switch, a metal base plate having an angular upstanding flange at one edge, an insulating base mounted on said bas plate and having a switch cavity in its lower face, a stationary switch contact member carried by the insulating base in said cavity and lying wholly beneath the surface of the insulation, a movable switch contact member lying within said cavity, formed and biased so as in part to descend below the surface of the cavity and thereby to engage said stationary contact, a movable switch actuating lever pivoted to said base in said cavity and having an inner end of insulating material movable beneath said movable switch contact member so as to enclose said stationary contact member within an arc extinguishing chamber, said actuating lever also having an outer end projecting from said base adjacent said flange and an operating lever pivoted between a part of said base and said flange, the inner end of said operating lever having an operative connection with the outer end of said switch actuating lever.

5. In a switch of the type wherein two metallic contacts biased towards one another are separable by an insulator interposable therebetween in order to open the switch, an insulating body having a first stationary contact member positioned a substantial distance beneath the surface of said-body, a second spring contact member formed and biased so that a portion thereof can enter below the surface of said insulating body and touch said first contact member, and an insulator slidable upon one surface of said insulating body and interposable between said two contact members so as to form a substantially completely enclosed arc extinguishing chamber about said first contact member when the switch is opened.

' HERMAN J. vHAMMERLY. 

